You need to call some one that makes oil, ask them, bite the bullet and use exactly what they say. You are a very rare case. The zinc is primarily in there to keep the cam alive. When the government decided to eliminate zinc from engine oil, for several reasons, it forced everyone to switch to roller lifters. Bet your butt the OEM's would still use flat tappet lifters if they could. But they can't, because zinc kills the cats, and with out zinc the cam dies a miserable death. I think any zinc will eventually get to th cat and kill it. More zinc, quicker death. Less zinc, slower death.
All that said, you need to call someone and follow what they say, and not let internet wizards guide your decisions. And yes, that includes me.
I use Torco, but some guys squeal at the cost. LAT is a top level oil with Torco, but it's price point is the same as Torco. Plus, I'm not sure LAT has any street oils. There is Driven. And Lucas. I'd call them all. Ask questions. Take notes. I wouldn't let price dictate what you do.
Torco
LAT
Driven
Lucas
Post up what they say. It may help someone else. But I doubt many are in your predicament.
